Method of producing steel billets



March1 3, 1945. ARROWE 2,371,356

METHOD OF PRODUCING STEEL BILLETS Filed July 20, 1943 I MQQ fTi PatentodMar; 13, 1945 METHOD OF PRODUCING STEEL BILLETS Andrew Rowe, MoKeesport,Pa assignor to National Tube Company, Pittsburgh, Pa., a corporation ofNew Jersey Application July 20, 1943, SerialNo. 495,471

2 Claims.

The invention relates to the production of steel "billets that aresubstantially rectangular in cross section, having rounded corners, andwhich are subsequently rolled or otherwise worked to form varioussections, seamless tubing, forgings and the like.

The prevailing practice in producing suchbillets is to roll ingots intoblooms on a reversing blooming mill which may be. a two-high or afourhigh mill whose working rolls are supported by backing rolls. andthen on the same heat to roll the blooms singly on a reversingthree-high mill or on a continuous mill which is used primarily forproducing the smaller size billets. The work ing rolls of such billetmills are provided with grooved passes that are formed between deepcollars that not infrequently spell and break, making it necessary toregrind the rolls or substitute new ones.

Before ,being rolled or otherwise worked, it is necessary to conditionthe four rolled surfaces oi each such singly rolled billet, as bychipping, grinding, i iame cutting or scarflns, which requires asubstantial amount of time, and not infrequently is attended by asubstantial loss of metal required to be removed.

-'1'he object of the invention is to provide an improved method ofproducing steel billets of the type explained, whereby the direct costof production is materially reduced and substantial indirect savings areattained by reduction in the wear and breakage of rolls and rollcollars.

In-the practice of my improved method steel billets are produced inmultiple from an ingot which is first rolled on a slabbing mill to forma slab having a thickness which is substantially equal to the thicknessof desired billets and having a width which is a multiple of that ofdesired billets. Any well known or desired procedure may be followed-toroll such slabs from east ingots. They may be rolled on eithertwo orfour-high reversing slabbing mills having vertical edging rolls in linewith horizontal slabbing'rolls, but preferably the slabbing rolls areprovided r with one or more edging passes and the working tablesadjacent to them are equipped to-turn the slabs on their edges andproperly guide them through the passes. v v

Aftera slab of the desired width and thickness has thus been produced itis, on the same heat, flat rolled in a closed pass to form desiredrounded corners at its longitudinal edges. and also simultaneously toform narrow shallow grooves on the upper andlow'er faces or the slab,the grooves 7 upper'being opposed to those on the lower face. Thesegrooveshave rounded corners and they are spaced from each other and fromthe edges of the slab the width of desired billets. While this groovingand corner-rounding pass may be formed in the rolls of a special millstand,

it is preferably formed in the working rolls of the slabbing mill. p

when the thus grooved slab has been formed it is flame cut'in the planeof the opposed grooves to form a plurality of billets, the flame cuttingbeing done by oxyacetylene or oxyhydrogen torches which simulttaneouslyfinish the flame cut faces of the billets and make it unnecessarysubsequently to condition them.

tive view of a grooved slab being flame out to produce a plurality ofbillets.

As shown in Fig.1, the faces of upper slabbing roll Iii and lowerslabbing roll it are provided with a slabbing-pass i, a preliminaryedging pass 2, a final edging pass 3 and a closed slab-grooving andcorner-rounding pass 4, Upper roll I is shown in its lowermost position,land is adapted to be I collars I on the faces of rolls Ill and ii.

outer portion 0 of each of these' collars is curved elevated in anydesired manner by rollbalances which urge it against screw-downs whichare turned to the required vertical position to form any desired passspread. An ingot is. reduced to a slab by giving it the required numberof passes in slabbing pass I and edging pass 2. When As shown in F18. 1,pass 4 is shaped to provide two grooves in the upper and two'in thelower i'ace of a slab, the grooves being formed by small tocorrespondingly form a rounded base at the bottom of each groove, and,between the outer portions of each collarand the adjoining cylindrlcalroll faces, eachroll is curved as at I to form rounded corners at theouter portions of the grooves. 'The edgesof pass 4 are iormed by collarsit which are curved as at It to form rounded corners at the longitudinaledges or a grooved slab. The curvatures it of pass 4 may be of slightlyless radius than the corresponding curvatures l8 in final edging pass 3to provide an initial underflll at the comers or pass 4. In rolling aslab in pass 4 these corner underfllls are filled by the displacement ofmetal incident to the forming of grooves by collar 1. Thus in pass 4there is nooverfill, and consequent formation of fins, in the plane ofthe meeting faces of the rolls at the-edges of the pass.

4 Pass 4 may be formed to provide any desired number of properly spacedgrooves in the upper and lower faces of a slab so that the slab maylater be flame cut into any desired number of billets of a given size.By way of example, and

not of limitation, the details of a' suitable pro- 4 cedure will beexplained for rolling slabs in multiples of three billets that are 4 1-:4 inches in cross section.- Starting witha steel ingot about 23 x 26inches and weighing about 12,500 pounds, it is first given about tenpasses in slabbing pass I to reduce it to a slab about 20 x 11 inches,as shown in Fig. 2. The slab is then turned on its edge and is givenfour ed ng passes in edging pass 2 to reduce it to about 15 x 12 inches,as shown in Fig. 3. The thus edged blank is then given four passes inslabbing pass I to reduce it to about 19 x 5 inches, as shown in Fig. 4,and is then-turned on its edge and given one or two edgin passes infinal edging and comerrounding pass 3 to shape it to the form shown inFig. 5 which is about 14 1: 4 inches. The slab is finally given one ormore passes in closed groove-forming pass 4 to provide its upper andlower faces with opposed narrow shallow grooves 20. These grooves maysuitably be about threesixteenths of an inch wide at their bases andone-half inch in depth. After the slab is thus rolled and grooved it isflame cut by torches 2i which burn slits through the slab of aboutthreesixteenths of an inch in width and leave the corners of the billetsrounded to the same curvature as the rounded edges of groove 20.

In the example given the tonnage rate or production oi grooved slabs ofthe form shown in Figs. 6 and 7 is three times "greater than that ofrolling billets singly according to the prevailing practice explainedabove. In other words, thirty tons of slabs of the form shown in Figs.

6 and 7 can be rolled in the time required for 5 practice. The overall'cost or flame cutting grooved slabs and conditioning their rolled facesis not more than that of conditioning all four .faces of billets rolledsingly according to the prevailing practice, and is usually less with anat- 10 tendant saving in cost oi billet production. In

addition to these direct savings in the cost or billet production, thereis less spalling and breakage of the shallow groove-forming collar I andof the working rolls than in the case of rolls which 16 are providedwith deep collars for rolling all four faces of billetssingly. Thisindirect reduction in cost of producing billets is substantial.

According to the rovisions of the patent statutes, I have explained theprinciple and mode 20 or operation of my invention, have illustrated thepreferred way of practicing it, and have given a specific example of oneprocedure. However. I desire to have it understood that, within thescope of the appended claims the invention may be practiced otherwisethan specifically illustrated and described.

Iclaim; I

l. The method of producing steel billets in multiple i'rom an ingot,comprising rolling an ingot to form a slab having a thickness which isrooves in the upper and lower faces thereof,

such grooves having rounded corners and being spaced from each other andfrom the edges of the slab the width of desired billets, and flamecuttingthe slab in the planes of said opposed grooves to form aplurality of billets and simultaneously to finish the so cut faces ofthe billets. 2. The method of producing steel billets from an ingot,comprising rolling an ingot on a slabblng mill to form a slab having athickness which is substantially equal to and a. width which is amultiple or that or desired billets, rolling the slab in a closed passprovided inthe rolls of said slabbing mill to form rounded comers atthelonw gltudinaledges of the slab and opposed grooves in the upper andlower races thereof. such grooves having rounded corners and beingspaced from each other and from the edges' of the slab the width ordesired billets, and flame cutting the slab in the planes or saidopposed grooves to form I. plurality of billets and simuitaneously tofinish the so cut faces of the billets.

. ANDREW REED ROWE.

